9520=x^2-15x+70

Solution for 9520=x^2-15x+70 equation:

9520=x^2-15x+70

We move all terms to the left:

9520-(x^2-15x+70)=0

We get rid of parentheses

-x^2+15x-70+9520=0

We add all the numbers together, and all the variables

-1x^2+15x+9450=0

a = -1; b = 15; c = +9450;
Δ = b2-4ac
Δ = 152-4·(-1)·9450
Δ = 38025
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{38025}=195$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(15)-195}{2*-1}=\frac{-210}{-2}
=+105
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(15)+195}{2*-1}=\frac{180}{-2}
=-90
$